The radial temperature around a sodium reactor heater assembly submerged in water is calculated using a model of the heater cross section found by conformal mapping. Thermocouple readings were also analyzed. When the heat flux is 5 x 10/sup 5/ Btu/hr-ft/sup 2/, a radial temperature drop of about 680 deg C across the center of the thermocouple well is calculated and found to be within 6% of the experimental value. Since most of this drop is across the 0.001-in. helium gap between the heater and its sleeve, it is concluded that the thermocouple will have to be bonded to the sleeve for dependable reading of true sleeve temperature. Drawings of the heater assembly and thermocouple are given. (D. L. C.)

Approximately 100 ternary and quaternary spongezirconium alloys were screened for structural and cladding applications in a natural-uranium-fueled heavy-watermolerated power reactor. The alloy additions studied included2 to 4 wt.% Sn, 0.5 to 2 wt.% Mo, and 1 to 3 wt.% Nb. The effect of 0.1 wt.% Fe and 0.05 wt.% Ni additions to the experimental alloys was evaluated. All compositions were are melted, rolled at 850 ction prod- C from a helium- atmosphere furnace, vacuum annealed 4 hr at 700 ction prod- C, and furnace cooled. Room- and elevated-temperature hardness measurements were used to estimate the tensile strengths of the alloys, while corrosion resistance was evaluated by 1000-hr exposures to static 300 ction prod- C water. (auth)

A study to improve the elevated-temperature strength of niobium by solloving has resulted not only- in greatly improved strengths at 1200 and 1470 deg F but also in the development of improved fabrication techniques for these alloys. The most important step in the fabric:ition procedure of niobium and niobium-base allows is the initial breakdown of the cast structure. The cast structure of 1.84 wt. 4 chromium, 3.21 wt.% chromium. 4.33 wt. ' zirconium, and 20.5 wt.% titanium-4.28 wt. = chromium allovs and unalloyed niobium was broken known by- forging ingots (protected from oxidation by molybdenum ciins) at 2550 deg F and rolling at 800 deg F. After the initiai breakdown of the cast structure, the alloy-s were coid roiied to a total of 95 per cent reduction with no difficulty .A second fabrication technique was employed for a second set of alloys. Unalloyed niobium and 1.29 wt. % chromium, 2.74 wt. 3 zirconium, 4.5 wt.% molybdenum, and 10 wt. % titanium-3 wt.% chromium alloys were forged and rolled at 1000 deg F to break down the cast structure and then cold rolled to 0.030-in. sheet. the sheet obtained by this technique showed moderate edge cracking. Tensite tests on the coid-worked …

The proposed increased water capacity for 100-K plants will increase the electrical load to be supplied. The load study showed that the capacity of the existing 13.8 kV system is adequate to carry the increased loads proposed for Project CG-775, while for the 5 kV system, an expanded power system is proposed. Likewise, the voltage regulation on the kV system bus will be excessive, and voltage regulators should be added.

This document details activities of the Fuels Preparation Department during the month of January 1960. (FI)

The Criteria for Speed of Control must be met for all cases being considered in the Expansion Studies. These Criteria are dependent upon the ratio Volume of water/volume of uranium in the process channel, the reactor power level, and the rate at which the vertical rods are released and inserted into the reactor. For those cases wherein the graphite channel is overbored by 0.200 inch., the criteria can generally be met for the power levels under consideration since the ratio of Vw/Vu is maintained adequately small by the use of large diameter fuel elements. If the graphite is not overbored, high pressure drop across the fuel element section must be maintained in order to maintain small values of Vw/Vu, which results in a substantial increase in the front header pressure. A method is developed in this document which ties together and defines the hydraulic and physics characteristics of the fuel-process channel geometry necessary to satisfy the Speed of Control Criteria over a range of feasible operating conditions. This study assumes no graphite overboring and employs throughout a smooth bore zircaloy process tube having an inside diameter of 1.650 inches. The fuel elements are self-supported., and the inner hole size was …

Production of Pu nitrate, UO{sub 3}, and unfabricated Pu metal met schedules. Decontamination performance of Purex process continued below standard. The cerium-144 cask is being redesigned. A ``powered ferret``, for driving a scintillation counter through a conduit to monitor ground activity beneath waste storage tanks, is being designed.

With the development of the zircaloy-2 clad uranium fuel element, it was necessary to develop a method of closing the end of the element after the extruded tubes were cut to the desired length. Regardless of the ultimate design of the closure, a satisfactory zircaloy-2 fusion welding technique had to be worked out. The first fully successful welding was performed with electron beam welding in a vacuum chamber. To make satisfactory welds, the electron beam welding involved time and equipment, plus undue maintenance on the equipment.